This invention relates to a foam-discharging, squeezable vesssel and, more particularly, it relates to a liquid foam-discharging, squeezable vessel which enables one to conduct rapid and repeated discharge of uniform and fine liquid foam by simple operation.
Conventional vessels for retaining a liquid detergent for cleaning panes or wall surfaces of bathrooms have the defect that, when applied to a perpendicular plane as a liquid, the detergent runs downward, thus failing to exhibit its function. Therefore, it has recently been proposed to discharge the detergent or like liquid as a foam.
For example, Japanese Examined Patent Publication No. 60-20262 discloses a liquid foam-discharging, squeezable vessel having an air inlet passage with a check valve and a separatedly positioned foam-generating passage, wherein the ratio of the area of opening for outlet pipe-holding pipe joint to the cross area of the inlet passage is limited to a particular range and wherein average size of the air-passing pores of a porous body provided on the way of the foam-generating passage is limited to a specific size.
Japanese Examined Utility Model Publication No. 63-13810 discloses a similar liquid foam-discharging, squeezable vessel wherein the foam-generating means comprises a porous plate provided on the upstream side and a net or nonwoven fabric on the downstream spaced from the porous plate.
On the other hand, there have been known those liquid foam-discharging, squeezable vessels which have a fine net provided in the nozzle. For example, Japanese Examined Utility Model Publication No. 57-147602 discloses a liquid foam-discharging, squeezable vessel which has a porous cylinder within a circular cap intended for foaming the retained liquid by introducing air and the liquid thereinto and, in addition, a net in the nozzle. Japanese Examined Utility Model No. 57-149802 discloses a liquid foam-discharging, squeezable vessel which similarly has a porous cylinder within a circular cap with the central portion of the porous cylinder being excluded and a valve being provided therein which functions to prevent a liquid content from passing therethrough from under the valve and to introduce air from outside. When the body of the disclosed vessel is squeezed, air and a liquid content are introduced into the porous cylinder, and the mixture is foamed upon being ejected from the porous cylinder, the foam being made finer by a net provided in the nozzle.
However, the vessel disclosed in Japanese Examined Patent Publication No. 60-20262 has the defects that, though it can eject a liquid foam in a well foamed state, it requires a sophisticated technique of controlling the ratio of opening area of pipe joint to cross area of inlet passage and the average size of cells of the porous body provided on the way of the foam-generating passage, and that, since the liquid is foamed upon passing through the porous body, the porous body undergoes gradual clogging.
The vessel disclosed in Japanese Examined Utility Model No. 63-13810 has the defect that, since foaming and air-sucking upon unsqueezing are conducted through one and the same pipe, squeezing and unsqueezing of the squeezable vessel can not be conducted at a high speed, thus ejection of liquid foam not being conducted smoothly.
In addition, the vessels described in Japanese Unexamined Utility Model Nos. 57-147602 and 57-149802 have the following defects, though they give finely foamed product. That is, since first foaming is conducted in the porous cylinder wherein the liquid and the air are mixed with each other and the second foaming is conducted with the net provided in the nozzle, the vessel described in Japanese Unexamined Utility Model No. 57-147602 allows the air to proceed through pores having larger pore size upon sucking air after discharge of liquid foam, whereas the vessel described in Japanese Unexamined Utility Model No. 57-149802 permits the air to proceed through the valve provided at the top of the porous cylinder. Thus, in both cases, the air travels through the pipe provided at the center of the vessels to reach the air space. That is, the sucked air travels through the liquid retained in the vessel to reach the air space, upon which foaming of the liquid takes place. This can cause insufficient intake of the air into the air space, or can cause gradual clogging of the porous cylinder. Such vessels are not suitable for repeatedly discharging liquid foam, and can only be used as vessels for shaving cream which require once or twice discharge of liquid foam.
The inventors have long studied for overcoming the above-described defects of the liquid foam-discharging squeezable vessel, and have formerly completed a vessel having two different fluid-passing mechanisms--one for foaming upon squeezing the vessel, and the other for sucking air upon unsqueezing the vessel. That is, the foaming operation is conducted in a fluid-passing mechanism using two screens, and the air-sucking operation is conducted through an independent check valve mechanism. This vessel has been filed as Japanese Utility Model Application Nos. H3-87879 and H3-87880.